AP0100CS datasheet(26/73 Pages) ONSEMI

26 / 73 page

AP0100CS HDR: Image Signal Processor (ISP)

Test Patterns

AP0100CS/D Rev. 6, Pub. 1/16 EN

©Semiconductor Components Industries, LLC,2016.

Color Correction and Aperture Correction

To achieve good color fidelity of the IFP output, interpolated RGB values of all pixels are

subjected to color correction. The IFP multiplies each vector of three pixel colors by a 3 x

3 color correction matrix. The three components of the resulting color vector are all

sums of three 10-bit numbers. The color correction matrix can be either programmed by

the user or automatically selected by the auto white balance (AWB) algorithm imple-

mented in the IFP. Color correction should ideally produce output colors that are

corrected for the spectral sensitivity and color crosstalk characteristics of the image

sensor. The optimal values of the color correction matrix elements depend on those

sensor characteristics and on the spectrum of light incident on the sensor. The color

correction variables can be adjusted through register settings.

Traditionally this would have been derived from two sets of CCM, one for Warm light like

Tungsten and the other for Daylight (the part would interpolate between the two

matrices). This is not an optimal solution for cameras used in a Cool White Fluorescent

(CWF) environment. A better solution is to provide three CCMs, which would include a

matrix for CWF (interpolation now between three matrices). The AP0100CS offers this

feature which will give the user improved color fidelity when under CWF type lighting.

To increase image sharpness, a programmable 2D aperture correction (sharpening filter)

is applied to color-corrected image data. The gain and threshold for 2D correction can

be defined through register settings.

Gamma Correction

The gamma correction curve is implemented as a piecewise linear function with 33 knee

points, taking 12-bit arguments and mapping them to 10-bit output. The abscissas of the

knee points are fixed at 0, 8, 16, 24, 32, 40, 48, 56, 64, 80, 96, 112, 128, 160, 192, 224, 256,

320, 384, 448, 512, 640, 768, 896, 1024, 1280, 1536, 1792, 2048, 2560, 3072, 3584, and 4096.

The 10-bit ordinates are programmable through variables.

The AP0100CS has the ability to calculate the 33-point knee points based on the tuning

of cam_ll_gamma and cam_ll_contrast_gradient_bright. The other method is for the

host to program the 33 knee point curve themselves.

Also included in this block is a Fade-to Black curve which sets all knee points to zero and

causes the image to go black in extreme low light conditions.

Color Kill

To remove high-or low-light color artifacts, a color kill circuit is included. It affects only

pixels whose luminance exceeds a certain preprogrammed threshold. The U and V

values of those pixels are attenuated proportionally to the difference between their lumi-

nance and the threshold.

YUV Color Filter

As an optional processing step, noise suppression by one-dimensional low-pass filtering

of Y and/or UV signals is possible. A 3- or 5-tap filter can be selected for each signal.

AP0100CS датащи(PDF) 26 Page - ON Semiconductor

AP0100CS датащи(HTML) 26 Page - ON Semiconductor

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73

датащи скачать

ссылки URL